To answer your question about a new yard in Monroe/Marshville for switching....like the one in Rocky Mount. No, it wouldn't make since to do this to reduce the log jams in Monroe. Hamlet, the largest CSX rail yard in NC is just to the east of Marshville. A yard like Rocky Mount or Hamlet isn't build to eliminate log jams, they're built to switch/build trains. Hamlet for CSX is much like a major airline hub is for airlines. CSX has 10 of these across their network. Monroe needs a turnout from the Charlotte Sub to the Monroe Sub (southbound) to help reduce some of the log jams. In addition to that a bypass around Monroe Yard allowing trains from the Charlotte Sub destined for Hamlet would also be helpful.
None of these options are cheap and I don't forsee anything happening anytime soon. With the federal mandate of Positive Train Contol, the railroad has to be really smart about building projects of this size. This more than the 2009 recession plays a big role in past plans. That's why the Pinoca Yard Ramp expansion project was done. It was a lot cheaper.